The spherical dome on a Van de Graaff generator has a diameter of 40 cm and the potential at its surface is 5.4 kV.
a. i. Calculate the charge on the dome.
ii. Calculate the capacitance of the dome.
An earthed metal plate is moved slowly towards the sphere but does not touch it. The sphere discharges through the air to the plate. This graph shows how the potential at the surface of the sphere changes during the discharge.

b. Calculate the energy that is dissipated during the discharge.
c. Suggest why the discharge ceases while there is still some charge on the dome.

Transcribed Image Text:

V/ kV 6.0 5.0 4.0 3.0 2.0- 1.0 0.05 0.1 0.15 0.2 t/s Figure 23.22